I. Field of the Invention
This invention relates generally to a surgical instrument for use in intravascular catheterization procedures, and more particularly to devices for positioning a hemostatic agent against a puncture entry wound in a blood vessel to stem the flow of blood therefrom following removal of the catheter and catheter introducer at the conclusion of the procedure.
II Discussion of the Prior Art
When performing angiography or angioplasty procedures, following the Seldinger technique, the angiography catheter or angioplasty catheter is generally introduced into the vascular system by first employing a sharpened hollow needle to penetrate the skin, the underlying muscle tissue, and to enter the selected blood vessel. Next, a guidewire is commonly inserted through the lumen of the hollow needle and made to enter the selected blood vessel. Following that, the needle is stripped off the guidewire and a combination of a dilator and an introducer (or an introducer alone) are fed over the guidewire and pushed through the skin until first the dilator and next the introducer enter the selected blood vessel. The guidewire may next be removed, and the selected catheter for carrying out the procedure is fed through the lumen of the introducer and advanced through the vascular system until the working end of the catheter is appropriately positioned. Depending upon the procedure, a dye may be injected through the catheter or a balloon expanded. Following the conclusion of the catheterization procedure, the working catheter will be withdrawn and, subsequently, the combination dilator and introducer will also be stripped out of the wound.
Because it is common practice to administer a blood thinning agent to the patient prior to many of the procedures, a problem exists in stemming the flow of blood through the puncture wound made in the vein or artery. Typically, it is necessary to maintain pressure over the region for at least 30 minutes. Even more time is required if the patient is hypertensive or anticoagulated. When human hand pressure is utilized, it is somewhat wasteful of professional time. Devices, such as pressure bandages, sand bags or clamps may be employed, but for these devices to work, the patient must be compliant and motionless for this prolonged period. Also, with obese patients, because of the significant amount of tissue between the skin and the penetrated vessel, good hemostatic pressure oftentimes cannot be obtained above the penetrated artery or vein. Thus, a need exists for a means for accelerating hemostasis.
In U.S. Pat. Nos. 4,852,568 and 4,890,612 to Kenneth Kensey, a device and method is described for sealing puncture or incision wounds created percutaneously during a surgical procedure. In accordance with the teachings of the Kensey patents, a collagen plug having an anchoring mechanism in the form of a filament or string attached, is passed through the introducer following removal of the working catheter and is allowed to enter the blood vessel to be sealed. The introducer is then removed from the body and the string is tensioned until the collagen plug affixed to its end abuts the surgically-created opening in the blood vessel proximate its interior wall. When the collagen material is exposed to body fluids, it swells to create a block for the wound in the vessel wall while the collagen itself acts as a blood clotting agent and accelerates hemostasis.
Problems exist with the approach set out in the aforereferenced Kensey patents. More particularly, any intraluminal deposition of a collagen can result in embolization, especially as the material begins to reabsorb. Particles may break off and float downstream to the point where they may lodge in a smaller vessel, causing an infarct to occur. Not only that, but collagen material acts as a nidus for platelet aggregation which assists in blood clotting. Hence, the intraluminal deposition of a hemostatic agent can initiate a thrombosis at the site.
U.S. Pat. No. 4,838,280 and U.S. Pat. No. 4,936,835 to John R. Haaga teach the idea of incorporating a hemostatic material as a part of a needle biopsy device so that following the gathering of the tissue sample, a hemostatic plug can be left in the void in the tissue from which the sample had been excised. The collagen plug that is left behind serves as a hemostatic agent for more rapidly stemming blood flow from the point of injection of the biopsy needle.
Applicants are also aware of a product produced by Datascope Inc. of Montvale, N.J., and sold under the trademark "VASOSEAL". That device comprises a kit including a guidewire, a needle clip, a skin dilator, an outer syringe barrel, an inner plunger, and two cylinders of compressed collagen material. In carrying out the blood vessel sealing procedure using the VASOSEAL apparatus, two operators are required. Before the original puncture needle is removed, a clip is placed on the shaft of the needle at the skin level to mark the distance down to the artery. The needle and clip are then placed up against a card having graduations printed thereon and one of a plurality of device lengths are selected. When the catheterization procedure is completed, all devices are removed except for a guidewire. One operator is needed to maintain compression upstream while another operator works on the puncture site. A skin dilator is advanced over the guidewire into the tissue to the measured level. A syringe barrel is then advanced over the skin dilator to the same measured level. The dilator and the guidewire are then removed. Next, a plunger is loaded with one of the two plugs of collagen and this is inserted into the syringe barrel and advanced down into the wound. The plunger is removed and reloaded with a second collagen plug and this, too, is inserted down into the syringe barrel into the wound. The main operator now takes over the job of applying a compression force over the area and holds the spot for several minutes. When no bleed-back or hematoma growth is seen, the operator removes the syringe and plunger.